Java Coding Problems

169. Implementing the Factory pattern

In a nutshell, the Factory pattern allows us to create several kinds of objects without exposing the instantiation process to the caller. This way, we can hide the complex and/or sensitive process of creating objects and expose an intuitive and easy-to-use factory of objects to the caller.

In a classic implementation, the Factory pattern relies on an intern switch(), as shown in the following example:

public static Fruit newInstance(Class<?> clazz) {  switch (clazz.getSimpleName()) {    case "Gac":      return new Gac();    case "Hemi":      return new Hemi();    case "Cantaloupe":      return new Cantaloupe();    default:      throw new IllegalArgumentException(        "Invalid clazz argument: " + clazz);  }}

Here, Gac, Hemi, and Cantaloupe ...